This invention relates to an auxiliary device of a drilling machine for determining a distance from the drilling machine to a workpiece and a related control method.
The auxiliary device according to the invention can be connected to a drilling machine or mounted to the drilling machine on a permanent basis. The auxiliary device may comprise detachable or permanent means for mounting to the drilling machine, e.g., clips, couplings, clamps, screws. The auxiliary device comprises a camera aligned in a working direction for recording an image of a working surface and a drill hole generated by the drilling machine. An image processing device is provided for identifying the drill hole in the image. Based on a virtual distance from the drill hole to a reference point in the image, an evaluation device determines a distance from the drilling machine to the workpiece. A display device serves to indicate the determined distance. The invention takes advantage of the fact that a virtual distance from the drill hole in the image expands to the optical axis or center of the image with diminishing distance. One optical axis of the camera is preferably parallel and staggered to a working axis of the drilling machine.
A control method for determining a distance of a drilling machine from a working surface provides the following steps: recording an image of a working surface including a drill hole generated by the drilling machine, identifying the drill hole in the image, determining a distance from the drilling machine to the workpiece based on a distance from the drill hole to a reference point in the image by an evaluation device, and indicating the determined distance by a display device. The image recognition device can identify a drill in the image. A visible end of the drill pointing to the optical axis may be determined and identified as the drill hole.
One embodiment provides that a projector for emitting a first light beam in a first direction, which generates a first light spot on the working surface, and a second light beam in a second direction, which generates a second light spot on the working surface, is provided, with the first and the second direction being different. The evaluation device is arranged to determine an inclination of the drilling machine to the workpiece based on a first distance of the first light spot recorded in the image to a reference point and a second distance of the second light spot recorded in the image to the reference point. The distance from the drilling machine to the workpiece as determined may also be taken into account to specify the inclination as absolute angles.
The following description explains the invention based on exemplary embodiments and figures.